You know the one where physical and aggressive actions are allowed up to a certain point.

Jallow seems to walk up to the line a lot. It's a line Purdue coach Jeff Brohm and safeties coach Anthony Poindexter don't want the 6-foot-2, 200-pound junior college transfer to cross.

In a way, it’s refreshing to see him – or anybody – try, based on recent results from the program’s defense.

He did cross it the second day of training camp. Jallow tried to knock the ball out of receiver Gregory Phillips’ hands as he was getting up off the ground after making a catch. Phillips objected. The two scuffled. Teammates joined in but coaches broke up the pile.

This is what you get with Jallow, who continues to make the transition from cornerback.

Enforcer. Intimidator. Toughness. All elements the Boilermakers need on defense, especially at the safety position. It’s part of who he is.

“My style as a player?” Jallow said. “Physical.”

The skirmish with Phillips echoed his point.

“You’ve seen a little flash the first couple of days,” Jallow said.

He comes to Purdue from East Mississippi Community College. He’s a native of Mississippi, calling Olive Branch his hometown. He’s featured in Netflix’s “Last Chance U,” a documentary focusing on players at EMCC.

He's shown he can run. He's shown he can hit. He's demonstrated he can tackle. He isn’t afraid of contact. That’s a start.

“He brings that physicality and that toughness that you need at the safety position,” senior cornerback Da’Wan Hunte said. “The mentality that he has – he’s going after it every play. He’s going to bring that wood every play. Just to have that guy back there that you can trust and lean on, it’s a great thing. He’s going to be great for us and I’m excited to see what he does for us this year.”

What would hold Jallow back?

Understanding the playbook and knowing his assignments. He can't be out of position. It’s a work in progress. Being the quarterback in the secondary the defense needs. Making sure the linebackers and defensive line are lined up properly.

“From spring to now, he’s been in the playbook,” Mosley said. “I can tell that now. When plays are called and he’s getting signals, he knows where you’re supposed to line up. If you put him in the position, he’s going to make the plays.”

The Boilermakers need playmakers. Offense and defense. Jallow has the tools to become a playmaker. Whether it’s making tackles, breaking up passes, interceptions or causing fumbles, Jallow needs to deliver for this defense to change its direction from the past.

Jallow’s mission – find the right balance. Maintain his aggressive approach, but do it with composure. Know when to stop and walk away. Play under control and keep his emotions from bubbling over into a situation that costs him, and his teammates.

Bring the swagger but know when it’s too much.

“He’s been better. He’s improving,” Brohm said. “He’s not going to hurt himself but the team, if he gets thrown out of the game. It’s important he practices that but I don’t want to take away his physical presence.

“Our receivers and players know he’s going to hit you, which is a good thing. Keep it between the whistles and we don’t allow anyone to instigate him as well and cause him to do something he’s not supposed to do.”